In military training maneuvers, drones are used to simulate enemy missiles closing in on a target. The drones themselves are programmed to follow various flight paths and in themselves constitute targets for the testing of missile defense systems.
One of the important functions programmed into the drone is a vertical profile of the path of travel of the drone towards a particular target. The vertical descent profile programmed is actually a continuously varying altitude command which is a function of the slant angle to the target.
A first type of vertical profile of the drone altitude might include a descent from a given altitude to a low altitude and thence a horizontal straight line low altitude approach directly to the target. A second type of vertical profile might simply be a straight line approach directly to the target from a given altitude, the drone traveling along the line of the slant range directly to the target.
To generate the foregoing types of altitude profiles for the drone, a computer is normally provided on the drone which will generate the necessary command altitudes as a function of slant range to the target. The slant range to the target is obtained from a standard TACAN receiver aboard the drone. The TACAN receiver is tuned to the target's TACAN transmitter frequency. The presently known methods of carrying out the altitude profile computation involve costly alternatives. Two such methods would be to store the required profile in a digital computer core memory or compute the profile equations as a function of range in a digital processor. Both arrangements would require a digital computer.
The primary disadvantage of the foregoing arrangement is the requirement of the digital computer itself. Not only is the computer costly, but adds substantially to the weight, volume and power requirements of the drone.